1. Field of the Invention
The present invention is directed to a striker driving assembly for a motor vehicle door lock.
2. Description of Related Art
Motor vehicle door locks having a motorized locking aid to increase ease of operation are known. Motorized locking aids are used, for example, for rear hatch locks, tailgate locks, and occasionally for locks of motor vehicle side doors.
Motor vehicle door locks are known in which the motorized locking aid is associated with the latch. A striker, in these motor vehicle door locks, is located securely on the component of the body opposite the latch (for example, a B pillar, a C pillar or the rear frame). The striker is used as the abutment for the latch, and by the motorized movement of the striker from a prelocking position into a main locking position, the motor vehicle door or hatch is shut tight.
The arrangement of the motorized locking aid on the latch, and thus on the motor vehicle door, can lead to construction problems. However, the problems can be solved by assigning the motorized locking aid to the striker. To do this, a striker driving assembly on or in the corresponding component of the body (for example, the B pillar, the C pillar or the rear frame) is employed. In this way, different advantages are achieved. For example, the independence of the actuating mechanism and the central locking system of the motor vehicle door lock from the driving means of the locking aid, is achieved. The possibility of emergency opening, which is necessary for safety reasons, is implemented since the actuation mechanism remains active for actuation by hand, with respect to the latch. It is not necessary to bypass the driving means for emergency opening by structural measures.
The basis for the invention resides a striker driving assembly with a striker carrier arranged to move linearly (as shown in U.S. Pat. No. 5,938,254 which corresponds to DE 197 37 996 A1). First of all, the striker located on the striker carrier is detachably and interchangeably arranged. The striker can be a wedge-shaped striker, a locking clamp, a locking pin or the like. The striker driving assembly can thus be used in a versatile manner for any motor vehicle type.
In known striker driving assemblies, the striker carrier is connected to a driving means which comprises an electric drive motor and gearing. In addition to the electric drive motor, other drive motors can also be used, such as hydraulic or pneumatic motors. The gearing can be a worm gear, toothed gearing, or the like. The striker carrier is arranged in a housing that allows for linear movement and the driving means is permanently joined to the housing.
The striker carrier, and thus, the striker, can be moved from a prelocking position into the main locking position using a cam. The pre-locking position is the position into which the striker is moved by manual locking of the corresponding component, such as a door. In the pre-locking position, the striker is held by the latch. The corresponding component is closed in this position, and a seal which is located on the body is not completely compressed so that, in particular, driving noise within the motor vehicle sounds loud. The main locking position is the position into which the striker can be moved out of the prelocking position. The seal is compressed in this position, between the body and the corresponding component of the motor vehicle.
A cam, by which the striker can be moved, is driven by the above-described driving means. The cam fits into a receiver which is located in the middle on the striker carrier. On the edge of the receiver, in the striker carrier, a power transmission surface is formed against which the cam comes to rest (with little friction), transferring force. The receiver is shaped such that the striker carrier can be moved by means of the cam from the prelocking position into the main locking position. In addition, the known striker driving assembly has a manual actuating means so that the striker can be moved from the prelocking position into the main locking position and fixed, even when the driving means fails.
The disadvantage of this prior art device is that the location of the cam drive is fixed by the cam, which is located in the middle in the striker carrier. For a narrow installation space, matching of the striker driving assembly to the existing space is not possible. Moreover, the point of application of force of the cam on the striker carrier during operation migrates sideways. In this way, the counterforce, which has been applied by the seal at the point of application of the force of the cam, is not permanently directed in the direction which is exactly opposite the application of force of the cam. This leads to nonuniform loading and increased wear.